Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, digital direct broadcast systems, wireless communication devices, personal digital assistants (PDAs), laptop computers, desktop computers, digital music and video players, handheld gaming devices, video game consoles, digital cameras, digital recording devices, cellular or satellite radio telephones, and the like. Digital video devices can provide significant improvements over conventional analog video systems in processing and transmitting video sequences with increased bandwidth efficiency.
Different video encoding standards have been established for encoding digital video sequences. The Moving Picture Experts Group (MPEG), for example, has developed a number of standards including MPEG-1, MPEG-2 and MPEG-4. Other examples include the International Telecommunication Union (ITU)-T H.263 standard, and the ITU-T H.264 standard and its counterpart, ISO/IEC MPEG-4, Part 10, i.e., Advanced Video Coding (AVC). These video encoding standards support improved transmission efficiency of video sequences by encoding data in a compressed manner.
Detection of ROI content may be desirable in a variety of video applications, including video event analysis and editing, video retrieval and browsing, video surveillance, video telephony, and video broadcasting. One example of an ROI is a human face, although other objects within a video scene may be important. In a video conference, for example, the ROI may present a participant's facial expressions or a drawing on a whiteboard. Using preferential encoding, the ROI may be presented with greater clarity and/or detail relative to other non-ROI areas.